Safety blow-off device for digesters and the like.



G. R. MEREWEATHER. SAFETY BLOW-OPF DEVICE POR DIGESTERS AND THE LIKE.

APBLIUATION FILED APR. 7, 191s.

1,088,1 62. Patented Feb. 24, 1914.

UNITED STATES PATENT OFFICE.,

GEORGE ROE MEREWEATHER, OF I-IULL, QUEBEC, CANADA, ASSIGNOR 0E ONE-HALF TO THE E. B. EDDY COMPANY, LIMITED, OF HULL, QUEBEC, CANADA.

Specification of Letters Patent.

` Patented Feb. 24, 1914.

Application led April 7, 1913. Serial No. 759,529.

To all whom it may concern.'

Be it known that I, GEORGE ROE MERE- WEATHER, a subject of the King of Great Britain, residing at Hull, in the Province of Quebec, in the Dominion of Canada, have invented certain new and useful Improvements in Safety Blow-Off Devices for Digesters and the like, ofwhich the following is the specification.

This invention relates to safety blow-off devices fordigesters and the like, and the objects are to provide a device of this kind which may be relied upon to permit a digester to blow off wh-enever the pressure becomes excessive.

It is quite usual to provide safety valves on digesters used in paper making and the like. The difficulty with such safety valves is that the gum and other material eXuded from the wood during the operation of the digester collects on the seat of such safety valve and causes the valve to adhere to the seat so that the valve will not relieve the digester at the required pressure. The present invention overcomes these difficulties by providing a liquid seal of mercury or like heavy liquid adapted to be blown by excessive pressure into a suitable collector, all as hereinafter more fully set forth and described in the accompanying specication and drawing.

The drawing shows a sectional elevation of the apparatus forming the present invention.

Referring to the drawing, A represents a digester or the like of well known construction.

B represents liquid containing means in the form of a U-shaped tube connected by a pipe 10 with the top of the digester, the connection between the pipe 10 and the digester being controlled by a valve 11 which is normally left open. The U-shaped tube is normally filled to a given height with heavy liquid such as mercury, the tube being relatively narrow so that considerable pressure will be required on the digester side to expel the mercury from the U-shaped tube. Y

The opposite side of the tube B to that which is connected to the digester leads to a collecting member C which has an outlet pipe or chimney 12 for the steam and other gases discharged from the digester. The collecting member is formed with a cylindrical collecting chamber 13 in which the mercury collects, the said chamber being connected by two short tubes 14 and 15 with unions 16 and 17, said unions being connected with short sections -of tubes 18 and 19 with a T 20 from which the ipe 12 leads.

The mercury may be with V rawn, if necessary, through a suitable stop cock 30.

The U-shaped tube B is connected by a pipe 21 with the union 17, and the T 2O is Y formed on the interior with an inclined baflie plate 22 against which the discharging gases from the digester impinge, said baffle plate being adapted to deflect the gases downwardly and prevent too rapid discharge through the outlet 1-2 and also to prevent loss of mercury in this way. From the lower part of the collecting chamber 13 a pipe 24 leads to the U-shaped tube B, the flowof liquid throughl the tube being controlled by a suitable valve 25 normally kept closed.

If desired, the resistance oli'ered by the liquid in the U-shaped tube may be increased by a suitable safety -valve 32 placed in the U-shaped tube and on the oppositeV side thereof to that to which the digester is connected. i

The operation of the device is as follows The valve 11.is normally kept open and the valve 25 closed. When any excessive pressure is created in the digester A the mercury contained in the tube B will be discharged through the pipe 21 into the collecting member and will flow through the pipes 14 and l5 into the collecting chamber 13, leaving an unobstructed passageway from the digester to the outlet pipe 12 and through which the digester may blow off.

As soon as the digester has been sufficiently relieved, the valve 11 is closed and the valve 25 opened, permitting the mercury to flow back into the U-tube B; thereupon the valve 25 is closed, the valve 11 opened and normal conditions thereby restored. F

As many changes could be made in the above construction and many apparently widely different embodiments ofl my invention within the scope of the claims, constructed without departing from the spirit or scope thereof, it is intended that all matcation and drawings, shall be interpreted as illustrative and not in a limiting sense.

vter contained in the accompanying speci- What I claim as my invention is:

l. A safety blow-od device for digesters, comprising a U-shaped tube containing a heavy liquid connected at one side to the digester, a collecting member comprising a collecting chamber, upwardly extending pipes thereon, unions connected to the pipes, a T, 'tubes connecting the T with the unions, a pipe connecting one of the unions with the U-shaped tube and an outlet pipe leading from the T.

, 2. A safety blow-off device for digesters, comprising a U-shaped tube containing a heavy liquid connected at one side to the digester, a collecting member comprising a Vcollecting chamber, upwardly extending pipes thereon, unions connected to the pipes, aT, tubes connecting the T 'with the unions,

l a pipe connecting one of the unions With the U-shaped tube and an outlet pipe leading from the T, and a baliie plate in the T;

3. Asafety blow-ofil device for digesters,

l compri-sing a U-shaped tube containing a heavy liquidf connectedat one'side to the -digester, a collecting member comprising a collecting chamber, upwardly extending ,pipes thereon, unions connected to the pipes,

a T, tubes connecting the T with the unions, a pipe connecting one of the unions with the U-shaped tube and an outlet pipe leading a T, tubes connecting the T with the unions,

a pipe connecting one of the unions With the U-shaped tube and an outlet pipe leading from the T, and a valve pipe connecting the collecting chamber with the U-shaped tube and means of increasing the resistance offered by the liquid in the said U-shaped tube consisting of a valve located in the pipe connecting one of the unions with the said U-shaped tube.

In Witness whereof I have hereunto set my hand in the presence of two Witnesses.

GEORGE ROE MEREWEATHER. Witnesses:

Y RUSSEL S. SMART,

PEARLE M. GARRoW.

Gopea of this patent may be obtained for ve cents each, by addressing the Commissioner of retenu` Washington, D. C. 

